Radial compressor

ABSTRACT

A radial compressor, with a compressor rotor, a compressor housing having a radially outer and a radially inner insert section, a main flow channel for supplying a medium toward the compressor rotor, a circulation chamber arranged radially outside of the main flow channel, which is separated from the main flow channel by a contour wall connected with the main flow channel via circulation openings to the insert section via struts extending into the circulation chamber. The main flow channel is bordered by the contour wall, and upstream from the contour wall by an upstream portion of the insert section. A suction element is arranged upstream from the compressor housing, whose radially outer portion adjoins the spiral housing section, and whose radially inner portion adjoins the upstream portion of the insert section. Adjoining surfaces of the suction element and the insert section lie on a cylindrical surface.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates to a radial compressor.

2. Description of the Related Art

FIG. 1 shows a basic structural design of a turbocharger 1 known from prior art. The turbocharger has a turbine 2 for releasing a first medium, in particular for releasing exhaust gas of an internal combustion engine and a compressor 3 for compressing a second medium, in particular charge air, specifically using the energy derived in the turbine 2 while releasing the first medium. The turbine 2 has a turbine housing 4 and a turbine rotor 5. The compressor 3 has a compressor housing 6 and a compressor rotor 7. The compressor rotor 7 is coupled with the turbine rotor 5 by a shaft 8, which is mounted in a bearing housing 9, wherein the bearing housing 9 is positioned between the turbine housing 4 and compressor housing 6, and connected with both the turbine housing 4 and compressor housing 6. FIG. 1 further shows a compressor-side silencer 10.

The compressor 3 of the turbocharger 1 shown on FIG. 1 is designed as a radial compressor. The compressor housing 6 of the radial compressor has a radially outer spiral housing section 11, as well as a radially inner insert section 12. A main flow channel 13 of the radial compressor 3, bordered radially outwardly by the compressor housing 6, is used to feed the medium to be compressed in a direction toward the compressor rotor 7. A circulation chamber 14 is formed outside of the main flow channel 13, specifically radially outside.

The circulation chamber 14 is bordered by a contour wall 15 of the main flow channel 13. The circulation chamber 14 is connected with the main flow channel 13 via circulation openings 16, 17. The contour wall 15 is connected with the insert section 12 by struts not shown in FIG. 1. According to FIG. 1, the main flow channel 13 is bordered upstream from the contour wall 15 by an upstream portion of the insert section 12.

According to FIG. 1, the silencer 10 is positioned upstream from the compressor housing 6, and provides a suction element 18 on the outlet side. The suction element 18 adjoins the spiral housing section 11 with a radially outer portion 18 a, and the upstream portion of the insert section 12 with a radially inner portion 18 b. In the radial compressor shown in FIG. 1, a flange connection 20 is provided between the radially outer portion 18 a of the suction element 18 and the spiral housing section 11 with the use of a clip 19.

If the compressor rotor 7 of the radial compressor 3 should break during operation of the latter, fragments of the compressor rotor 7 can impact the insert section 12, and displace it in the direction toward the suction element 18. In this process, the suction element 18 is then exposed to forces that can cause the connection 20 between the compressor housing 6 and suction element 18 to fail.

SUMMARY OF THE INVENTION

There exists a need for a radial compressor that poses no danger that a connection between the suction element and compressor housing will fail given a failure of the compressor rotor.

An object of one aspect of the invention is to provide a novel radial compressor.

According to one aspect of the invention, adjoining surfaces of the radially inner portion of the suction element and the upstream portion of the insert section lie on a cylindrical surface. If the compressor rotor of the compressor fails and fragments of the compressor rotor impact the insert section, the upstream portion of the insert section can move into the suction element in a defined manner, so that there exists no danger that forces acting on the insert section in the event of damage will lead to a failure of the connecting area between the spiral housing section of the compressor housing and the suction element.

In an advantageous further development, the respective surfaces of the radially inner portion of the suction element faces radially inward, and the adjoining surface of the upstream portion of the insert section faces radially outward, wherein the upstream portion of the insert section is positioned radially inward relative to the radially inner portion of the suction element. This configuration is especially preferred for enabling the upstream portion of the insert section to move into the suction element in the event of damage to the compressor rotor caused by fragments of the compressor motor impacting the insert section.

In an advantageous further development, the struts that connect the contour wall with the insert section engage a portion of the insert section that is offset radially outward relative to the upstream portion of the insert section and connected with the upstream portion of the insert section by a portion extending in the radial direction. A free space is formed between this portion of the insert section extending in the radial direction and the radially inner portion of the suction element. The free space defines a defined displacement path of the upstream portion of the insert section into the suction element.

In an advantageous further development, an undercut or material recess is formed on the upstream portion of the insert section, specifically at the axial position of the free space. This undercut or material recess prevents the upstream portion of the insert section in the suction element from tilting as the upstream portion of the insert section moves into the suction element in the event of damage to the compressor rotor.

Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred further developments of the invention may be gleaned from the subclaims and following description. Exemplary embodiments of the invention are explained in greater detail based on the drawing, without being limited thereto. Shown on:

FIG. 1: is a perspective cross section through a turbocharger known from prior art; and

FIG. 2: is a schematized meridian section through a radial compressor according to one aspect of the invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

FIG. 2 shows a meridian section through a radial compressor 21 according to one aspect of the invention, which in particular is designed as a radial compressor of an exhaust gas turbocharger.

The radial compressor 21 has a compressor rotor 22, which is arranged in a compressor housing 23. The compressor housing 23 has a radially outer spiral housing section 24, as well as a radially inner insert section 25, which in the exemplary embodiment shown is comprised of two segments 25 a, 25 b. The two segments 25 a, 25 b of the insert section 25 are configured as separate assemblies in the exemplary embodiment shown, and can also be integral in design.

The radial compressor 21 has a main flow channel 26, through which medium to be compressed can be guided toward the compressor rotor 22. A circulation chamber 27 is formed radially outside of the main flow channel 26, which is separated from the main flow channel 26 by a contour wall 28. The circulation chamber 27 is connected with the main flow channel 26 via circulation openings 29, 30.

Struts 31 extend inside the circulation chamber 27, and connect the contour wall 28 with the insert section 25, specifically with the segment 25 b of the insert section 25 on FIG. 2.

Therefore, sections of the main flow channel 26 are bordered radially outwardly by the contour wall 28. The main flow channel 26 is bordered upstream from the contour wall 28 by a downstream portion 32 of the insert section 25. The main flow channel 26 is bordered downstream from the contour wall 28 by a downstream portion 33 of the insert section 25, which outwardly adjoins the compressor rotor 22.

FIG. 2 further shows a suction element 34, which is arranged upstream from the compressor housing 23. The suction element 34 has a radially inner portion 34 a and a radially outer portion 34 b. The radially outer portion 34 b of the suction element 34 adjoins the spiral housing section 24. The radially inner portion 34 a of the suction element adjoins the upstream portion 32 of the insert section 25, which in the exemplary embodiment shown is provided by the segment 25 a of the insert section 25.

A flange connection 36 is formed between the flange-like, radially outer portion 34 b of the suction element 34 and a flange 35 of the spiral housing section 24.

In the radial compressor 21 according to one aspect of the invention, adjoining surfaces of the radially inner portion 34 a of the suction element 34 and upstream portion 32 of the insert section 25 lie on a cylindrical surface. The respective surface of the radially inner portion 34 a of the suction element 34 lying on this cylindrical surface here faces radially inward, and the respective surface of the upstream portion 32 of the insert section 25 lying on the cylindrical surface faces radially outward. The downstream portion 32 of the insert section 25 is positioned radially inwardly relative to the radially inner portion 34 of the suction element 34.

If the compressor rotor 22 breaks during operation and fragments thereof impact the insert section 25, the upstream portion 32 of the insert section 25 can move into the suction element 34 in a defined manner, so that the suction element 34 is not exposed to any forces that could lead to a failure of the flange connection 36.

As already explained, the contour wall 28 is connected with the insert section 25 via the struts 31 extending in the circulation space 27. The struts 31 here engage the portion 37 of the insert section 25 that is offset radially outwardly in relation to the upstream portion 32 of the insert section 25 and connected with the upstream portion 32 via a portion 38 extending in the radial direction. In the exemplary embodiment on FIG. 2, this portion 37 of the insert section 25 offset radially outward is provided by the segment 25 b of the insert section 25. In the exemplary embodiment shown, the portion 38 extending in the radial direction and connects the portion 37 with the downstream portion 32 of the insert section 25 is formed by the segment 25 a of the insert section 25. As already explained, the segments 25 a, 25 b can also be integral in design, in contrast to FIG. 2.

Arranged between this portion 38 of the insert section 25 extending in the radial direction, which connects the upstream portion 32 of the insert section 25 with the portion 37 of the insert section 25 offset radially outward relative to the upstream portion 32, and the radially inner portion 34 a of the suction element 34 is a free space 39, which forms a kind of deformation space and defines a possible axial entryway for the upstream portion 32 of the insert section 25 into the suction element 34. The free space 39 provides an axial freedom of movement for the upstream portion 32 of the insert section 25 in the event of damage.

In the exemplary embodiment shown, an undercut 40 or material recess is introduced in the upstream portion 32 of the insert section 25 between the portion 38 of the insert section 25 extending in the radial direction, which connects the upstream portion 32 of the insert section 25 with the radially outwardly offset portion 37 thereof, and the radially inner portion 34 a of the suction element 34.

The undercut 40 or material recess is radially inwardly arranged on the axial position of the free space 39, which can also be referred to as the axial deformation space, relative to the free space 39, and passes over into the latter.

The undercut 40 or material recess is directed radially inwardly in relation to the radially outwardly directed surface of the upstream portion 32 of the insert section 25, which lies opposite the radially inwardly directed surface of the radially inner portion 34 a of the suction element 34. If the insert section 25 should move into the suction element 34 in the event of damage, this undercut 40 or material recess prevents a tilting of the upstream portion 32 of the insert section 25 in the suction element 34.

The undercut 40 is continuous in design in the circumferential direction, and formed on a radially outer surface of the upstream portion 32 of the insert section 25.

As already explained, the multipart insert section 25 consists of the segments 25 a, 25 b in the exemplary embodiment shown. The latter can also consist of a single component, in which case the segments 25 a, 25 b are integral in design.

In the exemplary embodiment on FIG. 2, the insert section 25 and radially outer spiral housing section 24 of the compressor housing 24 are separated on the component side, so that the latter are thus provided by separate components. It is possible that the insert section 25 extend until into the spiral housing section 24, wherein sections of the spiral housing section 24 then consist of the insert section 25 as well.

In the event of damage to the compressor rotor 22 and the resultant axial displacement of the insert section 25 in the direction toward the suction element 34, the invention makes it possible to prevent a failure of the flange connection 36 between the compressor housing 23, namely in the spiral housing section 24 of the latter, and the suction element 34 from arising. As a consequence, this flange connection 36 is not exposed to any direct load in the event of damage. For this reason, the flange connection 36 can be given a more slender and lightweight design by comparison to conventional radial compressors.

Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto. 

What is claimed is:
 1. A radial compressor, comprising: a compressor rotor; a compressor housing, which has a radially outer spiral housing section and a radially inner insert section; a main flow channel configured to supply a medium to be compressed towards the compressor rotor; a circulation chamber arranged radially outside of the main flow channel; a contour wall that separates the circulation chamber from the main flow channel and is connected with the main flow channel via circulation, and which is connected with the radially inner insert section via struts extending into the circulation chamber, wherein the main flow channel is bordered by the contour wall, and upstream from the contour wall by an upstream portion of the radially inner insert section; and a suction element arranged upstream from the compressor housing, whose radially outer portion adjoins the spiral housing section, and whose radially inner portion adjoins the upstream portion of the radially inner insert section; wherein adjoining surfaces of the radially inner portion of the suction element and the upstream portion of the radially inner insert section lie on a cylindrical surface.
 2. The radial compressor according to claim 1, wherein respective surfaces of the radially inner portion of the suction element face radially inward, and an adjoining surface of the upstream portion of the radially inner insert section face radially outward.
 3. The radial compressor according to claim 1, wherein the upstream portion of the radially inner insert section is positioned radially inward relative to the radially inner portion of the suction element.
 4. The radial compressor according to claim 1, wherein the struts that connect the contour wall with the radially inner insert section engage a portion of the radially inner insert section that is offset radially outward relative to the upstream portion of the radially inner insert section and connected with the upstream portion of the radially inner insert section by a portion extending in a radial direction.
 5. The radial compressor according to claim 4, wherein a free space is formed between the portion extending in the radial direction of the radially inner insert section extending in the radial direction and the radially inner portion of the suction element.
 6. The radial compressor according to claim 1, wherein one of an undercut and a material recess is formed at the upstream portion of the radially inner insert section.
 7. The radial compressor according to claim 6, wherein the one of the undercut and the material recess is directed radially inward in relation to a radially outwardly directed surface of the upstream portion of the radially inner insert section.
 8. The radial compressor according to claim 1, wherein the radially inner insert section is integral in design.
 9. The radial compressor according to claim 1, wherein the radially inner insert section has a multipart design.
 10. The radial compressor according to claim 1, wherein the radially inner insert section and the radially outer spiral housing section of a stator-side compressor housing are separated on the component side and are provided by separate components.
 11. The radial compressor of claim 1, wherein the radial compressor is a radial compressor of an exhaust gas turbocharger. 